Yiğit Kalyoncu’s scientific contributions

One of the most prominent failure reasons for earth-fill dams is internal erosion resulting from piping. This failure mode may cause irreversible weakened structural integrity, loss of properties, and even loss of lives. Therefore, it is important to understand the breaching process due to piping by providing reliable data for the decision-makers in case of emergency. This study was supported by the Scientific and Technological Research Council of Turkey with project number 119M609 and involves experimental investigation on piping under three different weak zone scenarios to examine the breach process and provide the data for more realistic numerical evaluations. The experiments were conducted in the hydraulic laboratory of Izmir University of Economics and Dokuz Eylul University. The initiation of piping was triggered from seepage in weak layers at the bottom, middle, and upper parts, along the centerline of homogenous earth-fill dams in a rectangular flume. As a result of the experiments, the magnitude of the peak discharges and their durations as well as the eroded breach areas were found to be affected by the locations of the seepage and initial water heads acting on the weak zones. Also, in the experiments, at the beginning of the breaching, initial cascading surface flow resulted in sheet and rill erosion.

One of the most significant reasons for earth-fill dam failures is internal erosion resulting from piping. This research was carried out as a part of a project supported financially by the Scientific and Technological Research Council of Turkey (TÜBİTAK). This paper involves the comparison of the experimental findings related to two different scenarios to look into the breach process and to provide the data allowing the realization of more realistic numerical analyses. A circular tunnel of 2 cm diameter located 6 cm below the dam crest was created to induce the seepage. The experiments were conducted at Hydraulics Laboratory of Civil Engineering Department within İzmir University of Economics. The homogeneous earth-fill dams having a height of 0.60 m and a bottom width of 2 m were built in a flume 1.00 m wide, 0.81 m high and 5.44 m long. Some common soil mechanics tests were carried out before the dam was built. The dam bodies were constructed by using a mixture of 15 % clay and 85 % medium sand. High-precision cameras were used to record the temporal development of the breach resulting from the piping. The pump flow rate was measured by a magnetic flowmeter and the flow rate values outgoing from the breach were determined from the continuity equation. Gauss area formula was used to obtain the time-varied values of the breach areas. The temporal changes of water depth in the channel were also recorded. The so obtained experimental findings are presented and commented.

One of the most significant reasons for earth-fill dam failures is internal erosion, often known as piping. This research was carried out as part of a project funded by the Scientific and Technological Research Council of Turkey (TÜBİTAK) and it involves an experimental investigation to look into the breach process and provide the data for more realistic numerical evaluations. The experiments were conducted at Hydraulics Laboratory of Civil Engineering Department within İzmir University of Economics. The earthen dam with clay core 0.65 m high, a bottom width of 2 m and a crest width of 0.05 m was built in a flume 1.00 m wide, 0.81 m high and 5.44 m long. Some common soil mechanics tests were also carried out before the dam was built. The dam body was constructed by using a mixture of 15 % clay and 85 % sand. The clay core width was 15 cm at bottom and 1 cm at crest. The weak layer of a cross section of 5x5 cm2 was created by no-compacted soil mixture, and it was placed at 60 cm level from the bottom, along the centerline of the dam. High-precision cameras were used to record the temporal development of the breach resulting from the piping. The pump flow rate was measured by magnetic flowmeter and the flow rate values through the breach were determined from the continuity equation. Gauss Area formula was used to obtain the time-varied values of the total and wetted breach areas. The velocity values were calculated by dividing the flow rates through the breach to the corresponding wetted areas. The temporal changes of water depth in the channel were also recorded. The so obtained experimental findings are presented and commented.